Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
  • B01J13/02—Making microcapsules or microballoons
  • B01J13/06—Making microcapsules or microballoons by phase separation
  • B01J13/14—Polymerisation; cross-linking
  • B01J13/18—In situ polymerisation with all reactants being present in the same phase
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
  • B01J13/02—Making microcapsules or microballoons
  • B01J13/06—Making microcapsules or microballoons by phase separation
  • B01J13/14—Polymerisation; cross-linking
  • B01J13/18—In situ polymerisation with all reactants being present in the same phase
  • B01J13/185—In situ polymerisation with all reactants being present in the same phase in an organic phase
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/11—Encapsulated compositions
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
  • A01N25/26—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests in coated particulate form
  • A01N25/28—Microcapsules or nanocapsules
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23K—FODDER
  • A23K40/00—Shaping or working-up of animal feeding-stuffs
  • A23K40/30—Shaping or working-up of animal feeding-stuffs by encapsulating; by coating
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23P—SHAPING OR WORKING OF FOODSTUFFS, NOT FULLY COVERED BY A SINGLE OTHER SUBCLASS
  • A23P10/00—Shaping or working of foodstuffs characterised by the products
  • A23P10/30—Encapsulation of particles, e.g. foodstuff additives
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23P—SHAPING OR WORKING OF FOODSTUFFS, NOT FULLY COVERED BY A SINGLE OTHER SUBCLASS
  • A23P10/00—Shaping or working of foodstuffs characterised by the products
  • A23P10/30—Encapsulation of particles, e.g. foodstuff additives
  • A23P10/35—Encapsulation of particles, e.g. foodstuff additives with oils, lipids, monoglycerides or diglycerides
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/0241—Containing particulates characterized by their shape and/or structure
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/0241—Containing particulates characterized by their shape and/or structure
  • A61K8/025—Explicitly spheroidal or spherical shape
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/19—Cosmetics or similar toiletry preparations characterised by the composition containing inorganic ingredients
  • A61K8/25—Silicon; Compounds thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
  • A61K8/37—Esters of carboxylic acids
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/40—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing nitrogen
  • A61K8/41—Amines
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/49—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing heterocyclic compounds
  • A61K8/494—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing heterocyclic compounds with more than one nitrogen as the only hetero atom
  • A61K8/4966—Triazines or their condensed derivatives
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/55—Phosphorus compounds
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q17/00—Barrier preparations; Preparations brought into direct contact with the skin for affording protection against external influences, e.g. sunlight, X-rays or other harmful rays, corrosive materials, bacteria or insect stings
  • A61Q17/04—Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K2800/00—Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
  • A61K2800/40—Chemical, physico-chemical or functional or structural properties of particular ingredients
  • A61K2800/41—Particular ingredients further characterized by their size
  • A61K2800/412—Microsized, i.e. having sizes between 0.1 and 100 microns
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K2800/00—Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
  • A61K2800/40—Chemical, physico-chemical or functional or structural properties of particular ingredients
  • A61K2800/41—Particular ingredients further characterized by their size
  • A61K2800/413—Nanosized, i.e. having sizes below 100 nm
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K2800/00—Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
  • A61K2800/40—Chemical, physico-chemical or functional or structural properties of particular ingredients
  • A61K2800/60—Particulates further characterized by their structure or composition
  • A61K2800/61—Surface treated
  • A61K2800/62—Coated
  • A61K2800/621—Coated by inorganic compounds
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
  • Y10T428/2984—Microcapsule with fluid core [includes liposome]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
  • Y10T428/2989—Microcapsule with solid core [includes liposome]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
  • Y10T428/2991—Coated
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
  • Y10T428/2991—Coated
  • Y10T428/2993—Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Definitions

• the present invention relates to a cosmetic preparation comprising a capsule with a core/shell structure, comprising a core which comprises at least one sparingly water-soluble or water-insoluble organic active ingredient.
• the encapsulation of active ingredients is undertaken for various reasons. For example, through encapsulation it is possible to increase the storage stability of those active ingredients which are sensitive to light, oxygen or moisture.
• the active ingredient release can be influenced in a targeted manner by the encapsulation. Or liquid substances can be handled following encapsulation in the form of a pourable powder.
• encapsulation of organic UV filters for the area of sun protection of the human skin it is ensured through the encapsulation that the contact between human skin and the organic UV filter is reduced or even prevented.
• WO 2005/009604 A1 describes microcapsules with a high active ingredient content in which a core which comprises an active ingredient is surrounded by a shell, where the shell comprises an inorganic polymer.
• WO 2007/093252 A1 describes UV filter capsules which comprise at least one amino-substituted hydroxybenzophenone.
• WO 2009/012871 A2 describes UV filter capsules which comprise a polymeric coating, at least one sparingly soluble organic UV filter and an emollient as solvent for the sparingly soluble organic UV filter.
• WO 2010/013250 A2 discloses a composition comprising microcapsules comprising a core comprising a pharmaceutically or dermatologically active agent, and a shell, comprising metal oxide nanoparticles, where said nanoparticles are joined together by a hydrolyzed and polymerized sol-gel precursor.
• capsules which exhibit improved stability against unintended rupture of the shell or which have a denser, less porous shell in order to prevent the active ingredient from escaping.
• the capsules which can be used in the field of cosmetics should as far as possible release no skin-irritating constituents such as, for example, surfactants.
• the method for producing the capsules should be as widely usable as possible and easy to carry out. The method for producing the capsules should be stable both towards thermal stresses and also towards mechanical stresses.
• a capsule with a core/shell structure comprising a core which comprises at least one sparingly water-soluble or water-insoluble organic active ingredient, and a shell which directly surrounds the core, where the shell comprises nanoparticles of a metal oxide or semimetal oxide and these nanoparticles are joined together by at least one further metal oxide or semimetal oxide, where the further metal oxide or semimetal oxide joining the nanoparticles has been formed by hydrolysis and subsequent polycondensation of a water-insoluble or sparingly water-soluble sol-gel precursor.
• the capsule according to the invention comprises preferably less than 0.1% by weight, particularly preferably less than 0.001% by weight, very particularly preferably less than 0.00001% by weight, of low molecular weight, organic surfactants, in particular no low molecular weight, organic surfactants, based on the total weight of the capsule.
• No surfactants means that the capsule comprises no detectable amounts of low molecular weight organic surfactants and that no low molecular weight organic surfactant has been used in the production of the capsule.
• the capsule according to the invention preferably also comprises no high molecular weight protective colloids, such as, for example, gelatin, modified starch or pectins.
• the mass fraction of the core relative to the total mass of the capsule is usually greater than 50% by weight, preferably from 50 to 99% by weight, particularly preferably from 60 to 90% by weight.
• the percentages refer to a statistical mean value determined over a large number of capsules.
• the capsule according to the invention having a core/shell structure comprises in the inside in each case a core which comprises at least one sparingly water-soluble or water-insoluble organic active ingredient.
• the core may be either liquid or solid at 20°C. If the core is a solid at 20°C, this solid may be crystalline, partially crystalline or amorphous. If the core is a liquid at 20°C, this liquid may be homogeneous phase or a suspension.
• the core of the capsule according to the invention is a liquid at 20°C.
• the core in the inside of a capsule according to the invention consists preferably to more than 50% by weight, particularly preferably to more than 60% by weight, very particularly preferably to more than 80% by weight, in particular to more than 90% by weight, of at least one sparingly water-soluble or water-insoluble organic active ingredient, based on the mass of the core.
• the core consists preferably exclusively of the sparingly water-soluble or water-insoluble active ingredient.
• the core preferably exhibits hydrophobic properties, i.e. the core is only sparingly water-soluble or water-insoluble.
• the capsules according to the invention ordinarily have an average particle size (d50 value) of less than 1000 ⁇ m, preferably an average particle size of from 0.05 ⁇ m to 100 ⁇ m, particularly preferably a particle size of from 0.5 ⁇ m to 20 ⁇ m, in particular from 1 ⁇ m to 10 ⁇ m.
• the d50 value is defined as being that 50% by weight of the particles have a diameter which is less than the value which corresponds to the d50 value, and 50% by weight of the particles have a diameter which is larger than the value which corresponds to the d50 value.
• the d50 value can be read off from a particle size distribution curve, as can be generated, for example, by means of light scattering according to ISO 13320-1 (e.g. Microtrac S3500 Bluewave from Microtrac).
• a capsule according to the invention has a particle size of from 0.5 to 20 ⁇ m, in particular from 1 ⁇ m to 10 ⁇ m.
• the shells of the capsules according to the invention ordinarily have an average shell thickness of from 1 to 2000 nm, preferably from 1 to 200 nm.
• the ratio between the average thickness of the shell and the average diameter of the capsule is preferably from 1:50 to 1:500, particularly preferably from 1:100 to 1:200.
• the average particle size of the capsules and the thickness of the shells can be determined by means of TEM (transmission electron microscopy).
• the average particle size can be determined using the methods of light scattering (static and dynamic light scattering).
• the shape of the cores in the capsules according to the invention is arbitrary and can be, for example, irregular or spherical, preferably spherical.
• an organic UV filter selected from.
• Octocrylene Ethylhexyl Methoxycinnamate, Ethylhexyl Triazone, Diethylamino Hydroxybenzoyl Hexyl Benzoate, Methylene Bis-Benzotriazolyl Tetramethylbutylphenol or Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, and mixtures of these UV filters is used as sparingly water-soluble or water-soluble organic active ingredient.
• the sparingly water-soluble or water-insoluble organic active ingredient may be a liquid or a solid at 20°C, where the solid itself may also be present in a suitable lipophilic solvent, such as an oil, in dissolved form or as suspension.
• a suitable lipophilic solvent such as an oil, in dissolved form or as suspension.
• the sparingly water-soluble or water-insoluble organic active ingredient used in the capsule according to the invention is a liquid at 20°C.
• the core of the capsule according to the invention can also comprise hydrophobic auxiliaries such as oils or solvents which are usually used in the respective fields of application.
• hydrophobic auxiliaries such as oils or solvents which are usually used in the respective fields of application.
• the sparingly water-soluble or water-insoluble organic active ingredient can be dissolved or suspended in typical oil components, as are used in cosmetics.
• Customary oil components in cosmetics are, for example, paraffin oil, glyceryl stearate, isopropyl myristate, diisopropyl adipate, cetylstearyl 2-ethylhexanoate, hydrogenated polyisobutene, vaseline, caprylic/capric triglycerides, microcrystalline wax, lanolin and stearic acid.
• paraffin oil glyceryl stearate
• isopropyl myristate diisopropyl adipate
• cetylstearyl 2-ethylhexanoate hydrogenated polyisobutene
• vaseline aric/capric triglycerides
• caprylic/capric triglycerides microcrystalline wax
• lanolin and stearic acid stearic acid
• the shell of the capsule according to the invention which directly surrounds the core comprises nanoparticles of a metal oxide or semimetal oxide, where these nanoparticles are joined together by at least one further metal oxide or semimetal oxide, where the further metal oxide or semimetal oxide joining the nanoparticles has been formed by hydrolysis and subsequent polycondensation of a water-insoluble or sparingly water-soluble sol-gel precursor.
• the nanoparticles of a metal oxide or semimetal oxide usually have an average particle size of from 3 nm to 500 nm, preferably from 5 nm to 300 nm, particularly preferably from 5 nm to 150 nm, very particularly preferably 10 nm to 100 nm.
• the particle size of the nanoparticles can be determined by known methods, for example by means of TEM (transmission electron microscopy) or using the methods of light scattering (static and dynamic light scattering).
• the nanoparticles of a metal oxide or semimetal oxide used according to the invention are preferably approximately spherical.
• Suitable metal oxides or semimetal oxides for the nanoparticles are in particular those oxides which are sparingly soluble in water.
• Examples of preferred metal oxides or semimetal oxides suitable according to the invention are TiO 2 , ZrO 2 , HfO 2 , Fe 2 O 3 , ZnO, Al 2 O 3 and SiO 2 .
• Particular preference is given to silicon dioxide (SiO 2 ), in particular in the form of a silica gel.
• the nanoparticles of a metal oxide or semimetal oxide used according to the invention preferably have a charged, particularly preferably a negatively charged, surface and are thereby stabilized against aggregation. Particular preference is given to those nanoparticles which are stabilized against aggregation at a pH greater than 8, in particular in a pH range from 9 to 10.
• the nanoparticles of a metal oxide or semimetal oxide used according to the invention are particularly preferably nanoparticles of silica gel, in particular colloidal silica gel, where the particles are approximately spherical, nonporous and dispersible in water.
• these particles have a dense core and a surface covered with silanol groups (Si-OH).
• Si-OH silanol groups
• either some of the silanol groups on the silica gel surface are deprotonated through reaction with a base, i.e. are anionically modified, or are cationically modified through reaction with Al 3+ ions.
• preference is given to using anionically modified silica gel nanoparticles.
• Nanoparticles of silica are available for example from Grace under the name LUDOX in the form of aqueous dispersions.
• the surfaces of these nanoparticles of the silica gel have, as described above, a negative charge or a positive charge in order to prevent aggregation of the nanoparticles with one another.
• those nanoparticles of silica gel, the surface of which is negatively charged have proven to be particularly suitable.
• anionic silica gel types sodium cations or ammonium cations usually serve as counterions to the negatively charged surface.
• the further metal oxide or semimetal oxide present in the capsule according to the invention which has been formed by hydrolysis and subsequent polycondensation of a water-insoluble or sparingly water-soluble sol-gel precursor and joins the nanoparticles with one another, is usually an oxide that is sparingly soluble in water.
• preferred metal oxides or semimetal oxides suitable according to the invention are TiO 2 , ZrO 2 , HfO 2 , ZnO, Al 2 O 3 and SiO 2 .
• the metal oxide or semimetal oxide of the nanoparticles and the metal oxide or semimetal oxide formed by hydrolysis of the water-insoluble or sparingly water-soluble sol-gel precursor are in each case silicon dioxide, in particular a silica gel.
• Water-insoluble or sparingly water-soluble sol-gel precursors which can be used according to the invention are described, for example, in WO 2005/009604 A1 page 10, line 1 to page 11, line 11.
• Water-insoluble or sparingly water-soluble sol-gel precursors which can be used are preferably metal or semimetal alkoxide monomers, metal esters, semimetal esters or partially hydrolyzed and partially condensed polymers or mixtures thereof. These sol-gel precursors are preferably homogeneously miscible with the organic active ingredient. Particularly preferably, the organic active ingredient can be homogeneously dissolved in the sol-gel precursor, or the sol-gel precursor and the organic active ingredient form a homogeneous solution, it being necessary, if appropriate, to warm or heat the mixture. Alternatively, it is also possible to use a suitable organic solvent which is likewise immiscible or only poorly miscible with water, in order to provide a homogeneous solution comprising the active ingredient and the sol-gel precursor.
• Suitable and preferred sol-gel precursors are compounds of the formula M(R) n (P) m , in which M is a metal or semimetal, such as, for example, Si, Ti, Zr, Hf, Zn or Al, preferably Si, R is a hydrolyzable substituent and n is an integer from 2 to 4, P is a nonpolymerizable substituent and m is an integer from 0 to 4 or a partially hydrolyzed or partially condensed polymer thereof or some mixture thereof.
• M-R bond RH is cleaved off and forms a M-OH bond.
• two M-OH fragments react to form a M-O-M group with the elimination of water.
• hydrolyzable substituents R are alkoxy radicals, such as, for example, methanolate, ethanolate or isopropanolate, or carboxylate radicals, such as, for example, acetate, palmitate or stearate.
• tetraethyl orthosilicate tetraethoxysilane or Si(OEt) 4
• Si(OEt) 4 tetraethoxysilane or Si(OEt) 4
• tetraethyl orthosilicate as sol-gel precursor.
• the shell of the capsules according to the invention is preferably transparent, especially in the case of a UV filter as active ingredient.
• the present disclosure further provides a method for producing capsules with a core/shell structure, comprising in each case a core which comprises at least one sparingly water-soluble or water-insoluble organic active ingredient, and a shell which directly surrounds the core, where the shell comprises nanoparticles of a metal oxide or semimetal oxide and these nanoparticles are joined together by at least one further metal oxide or semimetal oxide, where the further metal oxide or semimetal oxide joining the nanoparticles has been formed by hydrolysis and subsequent polycondensation of a water-insoluble or sparingly water-soluble sol-gel precursor, comprising the steps
• step i) the preparation of an oil-in-water emulsion by emulsifying an oil phase which comprises at least one water-insoluble or sparingly water-soluble sol-gel precursor, and at least one sparingly water-soluble or water-insoluble organic active ingredient in a water phase which comprises nanoparticles of a metal oxide or semimetal oxide using shear forces is described.
• emulsifying centrifuges colloid mills or atomizers
• the person skilled in the art selects the suitable method and the appropriate emulsifying tool depending on the result desired, for example the desired droplet size in the emulsion, and depending on the physiochemical properties of the selected feed materials, for example their viscosity or else their thermal resistance.
• the fraction of the oil phase in the emulsion is preferably from 5 to 70% by weight, particularly preferably from 10 to 50% by weight, based on the total mass of the emulsion.
• the fraction of the mass of the water-insoluble or sparingly water-soluble sol-gel precursor in the overall mass of the oil phase to be emulsified is preferably in the range from 5 to 70% by weight, particularly preferably 20 to 50% by weight, based on the sol-gel precursor tetraethoxysilane.
• the mass fraction of this component relative to the overall mass of the oil phase can be calculated taking into consideration the different molar masses of the precursor compounds.
• the preferred sol-gel precursor in step i) is tetraethoxysilane (Si(OEt) 4 ).
• the nanoparticles of a metal oxide or semimetal oxide are present in the water phase before the emulsifying step usually in a concentration of from 0.01 to 4% by weight, preferably from 0.05 to 2% by weight, particularly preferably 0.1 to 1% by weight, based on the mass of the water phase.
• the mass of the colloidal silica gel used is preferably 1 to 15% by weight, particularly preferably 5 to 10% by weight, based on the mass of the oil phase.
• the preparation of the emulsion in step i) is usually carried out in the temperature range from 1°C to 90°C, preferably from 15°C to 25°C, in particular from 19°C to 23°C.
• a suitable pH for example by adding acid or base, the hydrolysis and polycondensation of the sol-gel precursor at the oil/water boundary is triggered.
• the suspension of capsules obtained at the end of step ii) can also be stabilized by adding additives such as, for example, nonionic, cationic or anionic polymers or surfactants or mixtures thereof.
• additives such as, for example, nonionic, cationic or anionic polymers or surfactants or mixtures thereof.
• the capsules according to the invention are notable for the fact that, during their production, the use of surfactants is largely or preferably completely dispensed with.
• the capsules with a core/shell structure produced in step ii) are, if appropriate, purified and/or isolated.
• Appropriate purification and isolation methods are known to the person skilled in the art, such as, for example, centrifugation, filtration, evaporation of the solvents, resuspension and dialysis methods. For example, by removing the solvents, in particular by removing the water, from the aqueous suspension of the capsules it is possible to obtain a powder.
• the capsules according to the invention with a core/shell structure are suitable, depending on the encapsulated active ingredient, as addition to cosmetics, pharmaceutical compositions, crop protection preparations, animal feeds, foods or nutritional supplements.
• the present disclosure further provides the use of the capsules with a core/shell structure which have been described above or which have been produced by the method described above as addition to cosmetics, pharmaceutical compositions, crop protection preparations, animal feeds, foods or nutritional supplements.
• the present invention further provides pulverulent or liquid preparations comprising the above-described capsules having a core/shell structure or the particles having a core/shell structure produced by the above-described method.
• the pulverulent or liquid preparations usually comprise at least one of the customary additives and/or auxiliaries which are known to the person skilled in the art for the particular field of application, such as, for example, in the field of cosmetics or pharmaceutical compositions, in the crop protection sector, in the animal feed, food or nutritional supplement field.
• pulverulent or liquid preparations as addition to cosmetics, pharmaceutical compositions, crop protection preparations, animal feeds, foods or nutritional supplements.
• the present invention provides cosmetics comprising the capsules according to the invention having a core/shell structure which have been described above or which have been produced by the above-described method. Particular preference is given to cosmetics for the area of skin protection against solar UV radiation.
• the oil phase was then homogenized with an aqueous solution of colloidal silica gel (LUDOX® LS 30) consisting of 7.2 g of silica gel (average particle size 12 nm; 220 m 2 surface area per g of silica gel; pH of the surface: 8), 3.6 g of sodium chloride and 288 g of water using a high-pressure homogenizer (M-110F Microfluidizer, Microfluidics) at 500 bar for 2 minutes.
• M-110F Microfluidizer Microfluidics
• Ethylhexyl Triazone (Uvinul® T 150) were dissolved at room temperature (22°C) in 50 g of ethyl acetate. 40 g of tetraethoxysilane were added thereto.
• the oil phase prepared in this way was homogenized at room temperature (22°C) with an aqueous solution of colloidal silica gel (LUDOX® TM 40) consisting of 1.0 g of silica gel (average particle size 22 nm; 140 m 2 surface area per g of silica gel; pH of the surface: 9) and 290 g of water using an ultrasound rod (200 W, 7 mm) for 2 minutes.
• the formed emulsion was admixed with stirring (magnetic stirrer) with 25 g of sodium tetraborate buffer solution (pH 9) and stirred for 24 hours.
• the samples A and B were in each case firstly spray-dried using a B-290 mini-spray dryer (Büchi, Switzerland).
• the spray-drying was carried out under the following conditions: entry temperature of ca. 120°C; exit temperature of ca. 55°C; use of a twin-material nozzle; use of nitrogen as spray gas.
• the fine powders were dried further for 30 minutes using a HR73 moisture analyzer from Mettler Toledo at 105°C.
• the weight loss of the powder from sample A before and after the drying at 105°C was ca. 4.5% by weight; the weight loss of the powder from sample B before and after drying at 105°C was ca. 9.0% by weight.
• the fine powders were dried further at 130°C for 15 minutes.
• the weight loss of the powder from sample A before and after drying at 130°C was ca. 7.8% by weight; the weight loss of the powder from sample B before and after drying at 130°C was ca. 13.2% by weight.
• the powder prepared from sample A exhibits better thermal stability than the powder prepared from sample B.

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• 2011
  • 2011-04-19 JP JP2013505445A patent/JP6054289B2/ja active Active
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